From another report, where there were at least 3, possibly 5 aircraft trying to coordinate and fly the same approach in IMC:
In Class G airspace, pilots are responsible for separation from other airspace users and from terrain.
IFR aircraft in Class G airspace are provided with a traffic information service by an Airservices Australia (Airservices) air traffic controller (controller) about conflicting IFR and observed visual flight rules aircraft. The traffic information is based on pilot reports and, where coverage exists, air traffic service (ATS) surveillance data. The obligation to provide the traffic information ceases when the pilot reports changing to the CTAF.
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The controller would not have been aware that the pilot was in instrument meteorological conditions, nor would the controller be aware of any position reports the pilot was making on the CTAF.
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The provision of traffic information and alerts by controllers, however, are supplemental to the pilot’s responsibility to ensure separation from other airspace uses and terrain in Class G airspace.